Inflatable medical assemblies

ABSTRACT

This invention provides inflatable, double-walled resilient sleeves for use in forming surgical casts about human and animal body members. In use, such a sleeve is first disposed about the body member and a liquid-curable material such as a foamable polyurethane prepolymer composition, is introduced into the space between the inner and outer walls of the sleeve to inflate the latter. Curing of the liquid material then provides the required rigidification of the sleeve. The invention also embraces the casts so formed and a method for forming the resilient sleeves, usefully by a dipping technique using a novel forming member.

United States Patent [72} Inventor Robert Howard Fryer Aberfoyle Mill,Aberl'oyle, Ontario, Canada 2i 1 App]. No. 825,667 [22] Filed May 19,1969 [45] Patented Jan. 4, 1972 [54] INFLATABLE MEDICAL ASSEMBLIES 3Claims, 8 Drawing Figs.

[52] 0.8. CI 128/90, l28/DIG. 20 [51] Int. Cl A6lf 5/04 [50] Field ofSearch 128/90, 87, 85, 89, DIG. 20

[56] References Cited UNITED STATES PATENTS 2,267,070 l2/l 941 Baldwin l28/165 3,403,676 10/1968 Gibbons Primary Examiner-Richard A. GaudetAssistant ExaminerJ. Yasko Attorney-Cecil C. Kent ABSTRACT: Thisinvention provides inflatable, doublewalled resilient sleeves for use informing surgical casts about human and animal body members. ln use, sucha sleeve is first disposed about the body member and a liquid-curablematerial such as a foamable polyurethane prepolymer composition, isintroduced into the space between the inner and outer walls of thesleeve to inflate the latter. Curing of the liquid material thenprovides the required rigidification of the sleeve. The invention alsoembraces the casts so formed and a method for forming the resilientsleeves, usefully by a dipping technique using a novel forming member.

INFLATABLE MEDICAL ASSEMBLIES The present invention relates to surgicalcasts and to a method of forming such casts whereby the setting offractures and the like may be facilitated. The invention also relates toinflatable sleeves for use in forming such casts and to forming membersfor use in the manufacture of such sleeves, as well as to a method forforming such sleeves.

A principal object of the present invention is to provide a surgicalcast free of many of the well-known problems and disadvantagesassociated with the use of plaster of Paris for such purpose.

A more particular object of the present invention is to provide asurgical cast which is convenient to apply, which is lightweight andwashable, and which is relatively transparent to X-rays.

It is yet another object of the present invention to provide a surgicalcast and a method of applying such a cast to a body member which castand method are characterized by their ease and rapidity of application.

A further object of the present invention is to provide surgical castswhich have wide application in the treatment of both human and animalfractures and the like.

Yet another object of the invention is to provide inflatable sleeveswhich may be used for fonning the surgical casts of the invention.

Other objects of this invention are to provide a method for fonning suchinflatable sleeves and novel forming members for use in such a method.

It is a further object of the present invention to provide a flexible,generally fluidtight sleeve for use in combination with the novelsurgical casts of the invention for drying a body member covered by sucha cast.

A novel surgical cast in accordance with the present invention isbroadly defined as comprising a double-walled resilient sleeve having aninner wall and an outer wall circumjacent said inner wall, said sleevebeing maintained in a rigidified, inflated condition by a solidifiedmaterial, such as foamed polyurethane, disposed between said inner andouter walls.

The invention also provides a method of forming a surgical cast about abody member which method comprises disposing an inflatable,double-walled resilient sleeve about said body member, introducing aliquid-curable composition, such as a foaming polyurethane composition,into the space between the walls of said sleeve to inflate said sleeveabout said body member, and curing said liquid composition to a solidstate within said sleeve.

The present invention also embraces in combination with a novel surgicalcast as hereinbefore defined, a flexible, generally fluidtight sleevehaving first and second resilient end cuffs, said first end cuffencircling said cast in a generally fluidtight manner and said secondend cuff being adapted to encircle in a generally fluidtight manner abody member extending from within said cast, and said flexible,generally fluidtight sleeve having an opening through which air may beblown for passage between said body member and the circumjacent surgicalcast.

An inflatable sleeve in accordance with the present invention broadlycomprises a resilient inner wall adapted to receive therethrough a bodymember and, circumjacent said inner wall, a resilient outer wall, saidinner and outer walls being terminally secured together in a fluidtightmanner to define a space therebetween, and an opening being providedinto said sleeve to permit the introduction of a liquid-curablecomposition into said space between said inner and outer walls.

The invention also provides a novel method for forming such a sleeve.Such a method comprises the steps of (a) forming a continuous tubularsleeve of resilient material on and around a forming member comprisingterminally adjacent first and second longitudinal portions, said firstlongitudinal portion having an external configuration corresponding tothe desired internal configuration of said double-walled resilientsleeve, and said second longitudinal portion having larger sectionaldimensions that said first longitudinal portion and having an externalconfiguration corresponding to the desired, uninflated, externalconfiguration of said double-walled resilient sleeve, (b) peeling saidtubular sleeve from said longitudinal second portion of said formingmember so that it is disposed as an outer wall circumjacent said tubularsleeve constituting an inner wall on said forming member, (c) bondingsaid inner and outer walls terminally together to form said inflatable,double-walled resilient sleeve, and (d) forming an opening in saidsleeve for the admission into the space between said inner and outerwalls of a curable liquid material.

As hereinbefore indicated, the invention also provides a forming memberfor use in forming the aforementioned resilient sleeves. Such a formingmember broadly comprises an elongated body having terminally contiguous,first and second longitudinal portions adapted to support integrallyformed inner and outer walls respectively of a resilient sleeve during aforming operation, said first and second longitudinal portions havingdifferent sectional dimensions such that, when said sleeve is peeledfrom said second longitudinal portion and disposed circumjacent saidsleeve from said first portion, a desired separation between said innerand outer walls of the sleeve is obtained.

Other objects, features and advantages of the invention will becomeapparent as the description herein proceeds.

The invention will now be described merely by way of illustration withreference to the accompanying drawings:

FIG. 1 is a perspective view of a surgical cast in accordance with theinvention showing it disposed around a patients forearm;

FIG. 2 is an enlarged, longitudinal sectional view through the surgicalcast of FIG. 1;

FIG. 3 is an enlarged, partial longitudinal sectional view through thesurgical cast of FIG. 1 showing a particularly useful feature of thatcast;

FIG. 4 is a similar sectional view to that of FIG. 2 but illustratingthe method according to the invention for forming a surgical cast andmore particularly showing the introduction of a foaming liquidcomposition into the space between the walls of an inflatable,double-walled resilient sleeve disposed around a patients forearm;

FIG. 5 is a representation of two deformable containers containing aprecursor material and an activator material, which materials areintermixed prior to the introduction of the resulting foamable mixtureas shown in FIG. 4 into the resilient sleeve of the surgical cast;

FIG. 6 is a front elevation showing the use of a forming member inaccordance with the invention for forming the inflatable, double-walledresilient sleeve of FIGS 2, 3 and 4 showing such a sleeve partly formed;

FIG. 7 is a longitudinal sectional view through the forming member ofFIG. 6 taken along the line 7 --7 of that figure and showing asubsequent stage in the sleeve-forming operation; and

FIG. 8 is a perspective view similar to that of FIG. 1 but also showingthe use with the surgical cast of that figure of a flexible, fluidtightsleeve suitable for drying the patients forearm under the cast, forexample, after bathing.

Referring first to FIGS. 1 to 3, it will be seen that the surgical castgenerally indicated therein at 10 and shown in position around apatients forearm 13 comprises an inflatable, double-walled resilientsleeve 11 having an inner wall 12 and an outer wall 14 circumjacent theinner wall 12. It will be noted particularly from FIG. 2 that the sleeve11 is closed at each of its ends 15 and 16. The walls 12 and 14 areusefully formed from an elastomer and, as will be explained hereinafter,such a sleeve 11 can readily be fonned by the novel forming method ofthe present invention using an elastomer latex dipping procedure.

A solidified liquid material such as a foamed resinous material 18, forexample, foamed polyurethane, is disposed within the space between thewalls 12 and 14 and this material 18 serves to maintain the sleeve 11 ininflated condition. Such material 18 also provides the requiredrigidification of the sleeve 1 1. It will also be appreciated that theactual rigidity of the cast 10 will vary according to the resilienciesof the sleeve 1 1 and of the material 18 as well as on the extent towhich the sleeve 1 1 is inflated on distended by the material 18contained therein.

It will also be seen from FIGS 1 and 2 that the foamed resinous material18 extends outwardly at 20 through an opening 21 in the outer wall 14 ofthe sleeve 11, this opening 21 being provided to permit the introductionof the resinous material 18 into the space between the walls 12 and 14as will be explained in more detail hereinafter with reference to theapplication of the cast 10 about a patients body member, for example,the patients forearm 13. It will further be understood that, once thecast 10 is formed, the opening 21 is sealed by the plug 20 of resinousmaterial.

lN accordance with useful feature of the invention, the inner surface ofthe inner wall 12 adapted to be disposed in surface contact with a bodymember, for example, the forearm 13, is formed with a plurality ofinwardly projecting protuberances or dimples 22 to pennit somecirculation of air between the cast 10 and the enclosed body member forsuch purposes as permitting drying of the skin, for example, afterbathing, or for allowing free evaporation of perspiration. If desired,the inner surface of the cast 10 may also be flocked as shown at 24 inFIG. 3.

In accordance with another useful feature of the invention, the cast 10is also usefully provided at each of its ends 15 and 16 with aresilient, preformed collar 25, 26 respectively, each of which isdisposed between the inner and outer walls 12 and 14 respectively. Suchcollars 25 26 provide some degree of dimensional stability to the cast10 while it is being positioned and filled about a body member as wellas facilitating the introduction of the material 18 into the spacebetween the walls 12 and 14. However another reason is to providecomfort should the wearer flex a limb, by providing resiliency, sincethe cast is hardened between the ends.

Having described the structure of the surgical cast 10, reference willnow be made to FIGS. 4 and to describe the manner in which the cast isformed about a body member such as the forearm 13. In such a procedure,the inflatable, double-walled resilient sleeve 11 in its deflated formis first disposed about the body member. It should be noted that, forthe particular sleeve 11 shown in FIG. 4, the collars 25 and 26 aresecured between the inner and outer walls 12 and 14 during themanufacture of such sleeve and that the opening 21 already mentioned isdefined by an outwardly extending nipple 28. Having disposed the sleeve11 correctly about the forearm 13, a liquid, curable resinouscomposition 30 is introduced into the space between the walls 12 and 14.The liquid resinous composition 30 is usefully introduced into thesleeve 11 from a primary deformable container or tube 32 (FIG. 4) havinga tubular neck 34 gripped by the nipple 28. Compression or otherdeformation of the container or tube 32 then forces the liquidcomposition 30 into the sleeve 11 as will readily be understood byreference to FIG. 4.

In accordance with another useful feature of the present invention, thetubular neck 34 of the primary container 32 is provided with an externalannular lip 35 which serves to provide a generally fluidtight engagementwith the nipple 28. Once the introduction of the liquid composition 30into the sleeve 11 has proceeded to the desired extent, the liquidmaterial is cured within the sleeve to a solid state to provide therequired rigidification of the cast 10. The primary tube 32 is thenremoved from the sleeve 11 and the protruding nipple 28 which is pluggedwith solidified material is then severed to provide a level outersurface for the cast 10.

Many suitable liquid curable compositions can be used for formingsurgical casts in accordance with the present invention. For instance,resinous liquid compositions can be used which are self-curing and whichare prepared a short time before use in view of their limitedshelflives. Alternatively, compositions may be used which have longshelf lives but which require the application of an external stimulussuch as heat, ultraviolet radiation, etc., to initiate or effect theircuring to a solid state. Obviously, the liquid material must be onewhich is capable of being cured to a solid state under conditions whichcan be tolerated by the body member contained within the cast.

Although the present invention embraces the use of nonfoaming liquidcompositions, particularly effective casts have been formed by the useof foamable compositions such as those comprising polyurethanematerials. With such materials, it is convenient to prepare the liquidcomposition 30 just prior to use and to introduce such a compositionimmediately into the sleeve 11 to allow the foaming to proceed the insitu. Such use of polyurethane compositions advantageous in that thecuring times of such compositions are very short, being of the order offive minutes or less.

With this procedure, the reactive component materials from which thefoamable liquid composition is prepared are usefully supplied inseparate containers for intermixing when required. For convenience, suchtwo-component systems will be referred to herein and in the claimsappended hereto as comprising a precursor material" and a separateactivator material." In the case of polyurethane compositions, theprecursor material may, for instance, comprise a suitable liquidprepolymer while the activator material may comprise a catalysteflective for completing the curing and foaming of the prepolymer to asolid foamed state. It should be under stood, however, that theinvention is not restricted to the use of any specific liquid curablecompositions and that many suitable combinations of precursor materialsand activator materials which will provide curable liquid compositionshaving the required properties can be used in the method of theinvention.

Referring now, merely by way of further illustration, to FIG. 5 of theaccompanying drawings, it can be explained that a precursor materialsuch as a liquid polyurethane prepolymer 31 is supplied in the primarydeformable container or tube 32, the tubular neck 34 of which has afemale thread 36 for engagement with a male-threaded closure cap 38. Asuitable activator material such as a catalyst 39 for use with theparticular prepolymer 31 is separately supplied in a secondarydeformable container or tub 40 having a neck 41 with a male thread 42and a cooperating female-threaded closure cap 43. For a reason whichwill become apparent as the description herein proceeds, the primarycontainer 32 is only partially filled with the prepolymer 31. Thethreads 36 and 42 of the containers or tubes 32 and 40 respectively areadapted to interengage as will be explained. When it is required toprepare the liquid material 30 for introduction into the sleeve 1 1 inthe manner already described, the closure caps 38 and 43 are removedfrom the tubes 32 and 40 respectively and the neck 41 of the secondarytube 40 is screwed into the neck 34 of the primary tube 32. The catalyst39 is then transfered from the secondary tube 40 to the primary tube 32by squeezing the former for thorough mixing in the primary tube 32 ofthe catalyst 39 with the prepolymer 31 contained therein. Such mixingcan be facilitated by the use of a resilient tube 32. The requiredmixing can then be effected by kneading the tube 32. It may also beadvantageous to incorporate a dye or other coloring agent into one ofthe component materials 31 and 39 so as to provide a visual indicationwhen the required degree of mixing has been obtained. In this case, thetube 32 may usefully be formed of a transparent or translucent material.When such mixing is complete, the liquid mixture is then transferredfrom the tube 32 into the sleeve 11 as already described with referenceto FIG. 4. Foaming of the liquid composition occurs rapidly as indicatedat 46 to inflate the sleeve 1 1.

Having described the use of the sleeve 11 for forming a surgical cast10, reference will now be made to FIGS. 6 and 7 to describe aparticularly useful procedure and a forming member in accordance withthe invention for forming such a sleeve 11.

Referring first to FIG. 7, it will be noted that a forming member ormould indicated generally therein at 50 comprises an elongated bodyhaving terminally contiguous, first and second,-frustoconicallongitudinal portions 51 and 52 with their larger ends disposedgenerally centrally at 53. For a reason which will be understood as thedescription herein proceeds, the second portion 52 has sectionaldimensions greater than those of the first portion 51. Consequently, ashoulder 54 is provided between the two portions 51 and 52.

The peripheral surface of the first or lower portion 51 of the formingmember 50 is provided with surface irregularities 56 which serve toprovide the aforementioned protuberances or dimples on the inner surfaceof the inner wall 12 of the sleeve 1 1 used in forming the surgical cast10.

In forming a sleeve such as sleeve 11 using the forming member 50, thelatter is first dipped into a bath 58 of rubber or other elastomer latex60 and then removed therefrom. Such dipping provides a surface coatingof latex on the forming member 50. This coating is then dried by anysuitable procedure, the coating on the first or lower portion 51 of theforming member 50 providing the inner wall 12 of the sleeve 1 l and thaton the second portion 52 providing the outer wall 14 of the sleeve 11.After the latex coating on the fonner 50 has dried sufficiently,resilient collars 25 and 26 are disposed about the first portion 51 ofthe fonning member 50 so as to be circumjacent the longitudinal ends ofthe inner wall 12. If desired, these collars 25 and 26 may be bonded inany ap propriate manner to the underlying inner wall 12, for example, bythe use of a suitable adhesive composition.

Referring further to FIG. 7, it will be seen that the upper or secondportion 52 of the forming member 50 is provided with an annular recess64 extending generally radially inwardly from its peripheral surface.During the aforementioned dipping operation, the latex 60 is receivedwithin this recess 64 to form the tubular nipple 28 utilizedsubsequently for introducing the curable liquid composition 30 into thesleeve 1 1.

With the collars 25 and 26 correctly disposed around the inner wall 12as shown in FIG. 6, the outer wall 14 is peeled from the second or upperportion 52 of the forming member 50 and disposed circumjacent the innerwall 12 around the lower portion 51 of the forming member 50 as shown inFIG. 7. The adjacent lower ends of the walls 12 and 14 are then bondedto each other in any suitable manner, for example, by a further latexdipping operation or by the use of a suitable adhesive composition.

It will be appreciated that, with the forming operation hereinbeforedescribed with reference to FIGS. 6 and 7, it will be necessary toremove the rubber end portion shown at 66 in first 7. This may beeffected before or after removal of the sleeve 11 from the formingmember 50. Although the sleeve 11 has been described as having a taperedconfiguration, it will be understood that sleeves of otherconfigurations, for example, cylindrical ones, may just as readily beformed in the manner described.

Referring finally to FIG. 8 of the accompanying drawings, there is showntherein, in combination with a cast 10 as already described, a flexible,generally fluidtight, fabric or plastic sleeve having first and second,resilient end cuffs 71 and 72. As will be seen, one of these cufi's, forexample, cuff 71, may be disposed so as to encircle the cast 10 in agenerally fluidtight manner in proximity to the end 16 thereof while thecufi 72 may then be disposed so as to encircle in a generally fluidtightmanner the patients arm extending from within the cast 10. The sleeve 70has an opening with an associated fitment through which air may be blownfor passage between the forearm l3 and the cast 10. Such a sleeve 70 isparticularly useful in that it permits air to be blown beneath the castfor drying purposes, for instance, if the body member is wetted, forexample, during bathing. The fitment 73 may usefully be adapted to beconnected releasably to a hose 74 from a vacuum cleaner, hair dryer orthe like.

What is claimed is: l. A surgical cast comprising a double-walledresilient sleeve having an inner wall and an outer wall circumjacentsaid inner wall, said sleeve being maintained in a rigidified, inflatedcondition by a solidified material disposed between said inner and outerwalls an opening extending through said outer wall said opening beingsealed by said solid material, said inner surface being adapted to bedisposed in surface contact with a body member, said inner surface beingformed with a plurality of inwardly projecting protuberances to permitcirculation of air between said cast and a body member enclosed thereby,and at least one resilient, preformed collar disposed between said innerand outer walls.

2. A surgical cast as defined in claim 1 which cast comprises first andsecond, resilient, preformed collars disposed between said inner andouter walls terminally thereof.

3. In combination, with a surgical cast comprising a doublewalledresilient sleeve having an inner wall and an outer wall circumjacentsaid inner wall, said sleeve being maintained in a rigidified, inflatedcondition by a solidified material disposed between said inner and outerwalls, a flexible generally fluidtight sleeve having first and secondresilient end cuffs, said first end cufi' encircling said cast in agenerally fluidtight manner and said second end cuff being adapted toencircle in a generally fluidtight manner a body member extending fromwithin said cast, and said flexible, generally fluidtight sleeve havingan opening through which air may be blown for passage between said bodymember and the circumjacent surgical cast.

* i t i I

2. A surgical cast as defined in claim 1 which cast comprises first andsecond, resilient, preformed collars disposed between said inner andouter walls terminally thereof.
 3. In combination, with a surgical castcomprising a double-walled resilient sleeve having an inner wall and anouter wall circumjacent said inner wall, said sleeve being maintained ina rigidified, inflated condition by a solidified material disposedbetween said inner and outer walls, a flexible, generally fluidtightsleeve having first and second resilient end cuffs, said first end cuffencircling said cast in a generally fluidtight manner and said secondend cuff being adapted to encircle in a generally fluidtight manner abody member extending from within said cast, and said flexible,generally fluidtight sleeve having an opening through which air may beblown for passage between said body member and the circumjacent surgicalcast.